The 3'-end region of the human PDGFR-β core promoter nuclease hypersensitive element forms a mixture of two unique end-insertion G-quadruplexes.

ABSTRACT: BACKGROUND:While the most stable G-quadruplex formed in the human PDGFR-β promoter nuclease hypersensitive element (NHE) is the 5'-mid G-quadruplex, the 3'-end sequence that contains a 3'-GGA run forms a less stable G-quadruplex. Recently, the 3'-end G-quadruplex was found to be a transcriptional repressor and can be selectively targeted by a small molecule for PDGFR-β downregulation. METHOD:We use 1D and 2D high-field NMR, in combination with Dimethylsulfate Footprinting, Circular Dichroism Spectroscopy, and Electrophoretic Mobility Shift Assay. RESULTS:We determine that the PDGFR-β extended 3'-end NHE sequence forms two novel end-insertion intramolecular G-quadruplexes that co-exist in equilibrium under physiological salt conditions. One G-quadruplex has a 3'-non-adjacent flanking guanin

SUBMITTER: Onel B 

PROVIDER: S-EPMC6183060 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature